Due to advancements in inverter equipment and the integration of electronic control circuits, a precise control of a rotation speed of a motor and a yarn breakage detection can be processed by means of a small-sized electronic circuit board. In a textile machine in which a number of spindle units, such as 100 to 200 spindle units, are arranged in a line, therefore, an individual motor is provided for each spindle unit, and a control board is provided for each motor so that there is adopted a system for simultaneously or individually controlling the rotation speed of each spindle by a control signal from the central control section.
To provide a drive motor and its control board individually for each spindle unit and to drive and control the motor and board individually, it is necessary to provide a power supply line and a control signal line to the motor and board, respectively. Therefore, as the number of spindle units increases, the number of wires for each motor or its control board also increases. As a result, the wiring lines are extremely complicated and difficult to service or adjust.
For example, if a yarn breakage or a fault occurs with a specific spindle unit, an operator must restore the spindle unit on-site. In the case in which a greater number of spindle units is used, and each spindle unit is arranged in a line in two spacedly parallel arrays, one in front of the unit and the other in the rear of the unit, the operator must walk a long distance from the front array to the rear array, thus hampering maintenance efficiency. In addition, work efficiency is also lowered by the fact that when these control boards are mounted, the operator must mount them while moving from the front array to the rear array.